'translate' a nil value on iOS only

Solar2D iOS
#1

Hello,

I’ve got a problem that doesn’t occur in the simulator or on an Android device - it only occurs on iOS.

I have a an “infinite” scrolling background where I place one behind the other every time one goes off the screen.  I create the background like this:

local backgroundOverlay = {}--display.newImageRect(bgOverlayLocation,w,h),display.newImageRect(bgOverlayLocation,w,h)} for i = 1, numThemes + 2 do table.insert(backgroundOverlay,display.newImageRect(bgOverlayLocation,w,h)); backgroundOverlay[i].anchorX = 0; backgroundOverlay[i].anchorY = 0; backgroundOverlay[i].alpha = .7 backgroundOverlay[i].y = 0 ; backgroundOverlay[i].x = (i-1)\*w + screenOriginX; group:insert(backgroundOverlay[i]); end

Then in my Enter Scene function, I run the scrollBackground() function every time which looks like this:

function scrollBackgroun() for i = 1, #backgroundOverlay do backgroundOverlay[i]:translate(-t\*cloudMoveSpeed,0); end end

It works just as it should on Android and both iOS and Android Simulators, but throws an exception in iOS saying ‘Attempt to call method ‘translate’ a nill value’;

I’m sure I did something wrong, but I can’t seem to figure out what.  If you have any pointers as to where to go next, I’d appreciate it.

#2

what is the value of the variable “bgOverlayLocation”?

#3

You might want to put in some prints and check to see what the value of “i” is, make sure that backgroundOverlay[i] is not nil, and perhaps print out the table values of that and see if for some reason the translate method is getting trampled on somwhere.

Rob

#4

I figured it out and will post here in case anyone has a similar issue.

The error actually did occur on the simulator, but not till I had changed a few senes.

I was using storyboard, and for some reason the exitScene method wasn’t being called.  I went ahead and updated the project to use composer and that took care of everything.  Hurray for composer!

#5

what is the value of the variable “bgOverlayLocation”?

#6

You might want to put in some prints and check to see what the value of “i” is, make sure that backgroundOverlay[i] is not nil, and perhaps print out the table values of that and see if for some reason the translate method is getting trampled on somwhere.

Rob

#7

I figured it out and will post here in case anyone has a similar issue.

The error actually did occur on the simulator, but not till I had changed a few senes.

I was using storyboard, and for some reason the exitScene method wasn’t being called.  I went ahead and updated the project to use composer and that took care of everything.  Hurray for composer!